Circuit switch



July 19,1938. T Q STILES 2,124,379

CIRCUIT SWITCH Filed July 6, 1935 2 Sheets-Sheet 2 INVENTOR. Tvma ga/yeffz/@J ATTORNEY.

Patented July 19, 1938 UNI-TED STATES PATENT OFFICE 3 Claims.

The invention relates to improvements in circuit switches and more particularly to that class of switches installed in signal circuits at highway crossings, automatic interlockings on railroads, and like places, which are employed for the daily tests of the circuits at such places.

Switches of the character referred to are located in boxes or cases for protection against the weather and manipulation by unauthorized persons and usually comprise a movable switch member, which latter, for the purpose of testing the circuits, is adapted to be pulled in one direction to break the circuit and thereafter returned to its normal position to make or restore the circuit. In some instances the operator or tester, after pulling the switch, neglects to return the same to its normal position with resulting failure in the normal operation of the signals,

With the foregoing in mind, it has been the main object of my present invention to provide a simple and efficient means for positively assuring the return of the switches to normal position after being pulled for test purposes. This object I attain by the new and novel means constituting my invention as hereinafter set forth in detail in connection with the accompanying drawings, in which- Fig. 1 is a front elevation of a switch box, with the cover partly broken away, containing test switches embodying my invention.

Fig. 2 is a cross section on the line 2 2 of Fig. 1.

Fig. 3 is a similar View showing the switches pulled and the cover in partially closed position engaging with one of the switch supporting pull-rods.

Fig. 4 is a section on line 4 4 of Fig. 1.

Fig. 5 is a detail of one of the switch pull-rods with the parts supported thereon in section.

To explain in detail, l represents the box for containing the test switch and may be made of any suitable material or design, the same preferably being made of cast iron or aluminum. This box, as here shown, comprises the body portion l, of generally rectangular shape, and a cover 2, the latter being hinged at one side to the body portion at 3 and at its opposite side being provided with a short arm or extension 4 adapted to be engaged by a hasp 5 hinged to the front of the box at 6. The arm of extension 4 adjacent its outer end is provided with an opening 'l to receive a padlock (not shown) or like fastening device for securing the hasp in its locking engagement with the cover. The box is also preferably formed at its inner or base side with laterally extended perforated lugs El to receive fastening screws or bolts for attaching the box to its support.

The box l may be of a size to contain any desired number of switch units, according to the number of circuits in connection with which it may be employed. As here shown, it contains four switch units of two circuits each, but as these are of like construction and operation, a description of one will be sufficient for the purposes of the present invention. Such unit comprises a base block l of insulating material which is adapted to be rmly secured to the back of the box; by suitable fastening means, such. as the screws il threaded into the back wall of the box and engaging the block through suitable openings therein. Mounted on the front side of this block is a. generally U-shaped bracket I4 which is secured at its base to the block by suitable iastening means, such as the screws l5, and formed at its outer ends with laterally extended bracket means l5, i6 which are perforated to receive and guide the outer ends of switch operating members or pull-rods l 1, which latter at their rear ends are slidably fitted, by means tobe presently described, within guide openings in the base block l0, thereby being' capable of axial movement. These switch operating members, which are here shown in the form of rods, are provided at their outer ends, at a point forward of the brackets I 6, with attached knobs Il of formica or other insulating material, as a convenient means for operating the same. These knobs may be attached to the rods in any suitable way, the same as here shown (see Fig. 5) being screw-threaded onto the same.

Mounted upon each of the slide members Il are two collars or ferrules, one of which, indicated at 2U, is of conducting material and constitutes the switch member, and the other, indicated at 2l, is of insulating or non-conducting material. The collar 2U, when held in normal or closed position by its supporting rod Il, engages with spring contact fingers 22, 22 which are connected with the usual terminal posts 23, 23, mounted on the base block l0 at opposite sides of the switch member. 'I'he circuit wires (not shown) for connection with said terminal posts enter the box through suitable openings therein; one such opening, 24, being in the lower end wall of the box, and two openings 25, 25, in the rear wall of the box.

The switch carrying rods Il, which I term pull-rods, in accordance with my invention will be of such length as to bring the knobs l1 at their outer ends into the path of movement of the box cover upon the closing of the latter, whereby they will be positively returned to their normal closed position with the switches closed, by said cover upon the complete closing of the latter. For example, the switch operator will open the cover 2 to expose the switches and then pull the latter outward to break the circuit, as shown in Fig. 3. not been pushed in or restored to circuit closing position by the operator, the cover upon being closed will engage with the projected pull-rods, as shown in Fig. 3, and will push them to their normal closed position as shown in Figs. l, 2 and 4. 1n this way, return of the switches to normal position is positively assured by the closing of the box cover in the event of such return having been inadvertently overlooked by the operator.

The collars 2D and 2l are positioned on the pull-rods so as to alternately engage and disengage with the cooperative contact springs upon the pulling and closing of the pull-rods. As here shown they are removably retained in such position on the pull-rod between two shoulders thereon, one of which, indicated at 3U, is formed on the rod itself, and the other, indicated at 3|, being in the form of a nut threaded on the inner end of the rod. 'Ihe collars 2!) and 2l being thus removably hel-d on the pull-rod, are thereby capable of being readily reversed, as shown in Fig. 5, to permit of the switch being adapted for either normal open or closed circuits.

The nut 3l after being set to secure the collars on the pull-rod, is preferably held against movement by a second or lock-nut 32 threaded onto the end of the rod, which second nut, in accordance with my invention, is formed with an eX- tension 33 sli-dably tting into a correspondingly shaped guide opening 34 in the base block I0 and thereby serving to support and guide the pull-rod at its inner end.

What I claim is:

1. The combination with a support of insulating material having a guide opening therein, of a circuit switch mounted thereon comprising op- Thereafter, if the switches have f posed contact iingers and an intermediate cooperative switch member, the latter consisting of a longitudinally movable pull-rod having removably mounted thereon two collars, one of conducting and the other of non-conducting material, for alternate engagement with the contact fingers, said collars being reversible in position on the pull-rod for providing normal open or closed circuits as desired, and a nut threaded onto the end of the pull-ro-d for retaining the said collars thereon, said nut having an extension slidably fitted into the said guide opening in the support to serve as a guide for the pull-rod in its switch operating movements.

2. The device of claim l wherein said support of insulating material and said circuit switch are mounted within a casing having a cover and wherein said pull rod extends into the path of said cover when in its open position and is positively moved by said cover to its closed position upon closure oi said cover.

3. The combination of a casing, a cover for said casing, insulating material mounted within said casing having guide openings therein, a plurality of circuit switches housed in said casing n and mounted on said insulating material, sai-d switches comprising opposed contact ngers and intermediate cooperative switch members, the latter consisting of longitudinally movable pullrods having removably mounted thereon collars of conducting and non-conducting material for alternate engagement with said contact lingers, said collars being reversible in position on said pull-rods for providing normal open or closed circuits as desired, and nuts threaded on the ends of said pull-rods for retaining said collars thereon, said nuts having extensions slidably tted into the said guide openings in said insulating material to serve as gui-des for the pull-rods in their switch operating movements; said pull-rods extending into the path of said cover when in their open positionsand being positively moved by said cover to their closed positions upon closure of said cover.

THOMAS GEORGE STLES. 

